Cell Sorter Technolgy

A researcher works to identify subpopulations of cancer cells using a fluorescence activated cell sorter. Invented at Stanford in the late 1960s by Leonard Herzenberg, professor of genetics, the FACS device stains and sorts live cells from samples of human tissue according to the unique antibody signature of each cell type. Modern sorters can process up to several million cells per minute.

Program researchers are searching for cancer stem cells – adult stem cells that underlie cancers of the blood, breast, ovaries, lung, brain and bladder, among others. In most cases, adult stem cells facilitate the body’s ability to repair itself, dividing and replenishing differentiated cells in bone marrow, brain, muscle and other tissues. In contrast, cancer stem cells damage the body, using the same process of self-renewal to produce new cancer cells and cause cancerous growth.

Program researchers use the FACS to separate heterogeneous samples of cancer cells. The sorter firsts treats the cells with antibodies that have been uniquely coupled with fluorescent dyes. After the antibodies bind to specific antigen proteins on the surface of each cell type, the cells are then sent single file through a laser beam. As each one crosses the laser, it emits a light characteristic of the antibody signature of its cell type. This is in turn detected by a photocell and used to identify subpopulations of cells.

By isolating a pure population of stem cells for each cancer, researchers hope to explore the genetic mutations that cause these cells to act abnormally and ultimately to develop more targeted cancer therapies.